Quick disconnect coupler

ABSTRACT

A quick disconnect coupler includes a seal retaining member movably mounted in a coupler housing. A sealing washer biases the retaining member toward first position, and an annular seal is mounted in the retaining member. This annular seal defines both axial and radial sealing surfaces, and it is configured to transmit sufficient force to the seal retaining member to move the seal retaining member to a rearward position in response to a first, larger diameter plug bearing on the axial sealing surface, and to form a radial seal around a second, smaller diameter plug.

This is a continuation of U.S. application Ser. No. 07/652,853, filedFeb. 8, 1991 now U.S. Pat. No. 5,167,398.

BACKGROUND OF THE INVENTION

This invention relates to a quick disconnect coupler having a seal whichcan be shaped to seal against all three of the commonly used couplerplugs.

Quick disconnect couplers are in widespread use for releasably joiningpneumatic and fluid transfer lines. In general, quick disconnectcouplers use hardened balls or pins which engage a groove in the couplerplug to hold it securely against a soft seal while permitting theassembly to swivel, thereby preventing kinking or twisting of hoses. Asliding sleeve is manually retracted to release the locking balls orpins, thereby permitting the plug to be inserted or removed. The sleeveautomatically returns to the lock position when released. Generally, anautomatic shut-off valve is provided in the coupler to seal the centralpassageway of the coupler automatically upon uncoupling. This eliminatesthe need for a separate shut-off.

In the past, a number of sealing approaches have been used to seal thehousing of the coupler to the coupler plug. One approach is to use anO-ring shown for example in Karcher, et. al., U.S. Pat. No. 4,833,951. Asecond approach is to use a cylindrical sealing surface that provides aradial seal, as shown for example in Gailey, U.S. Pat. No. 4,825,893. Athird approach is to use a cut washer which abuts the extreme endsurface of the coupler plug to provide the required seal. See, forexample, the quick disconnect couplers shown on page 4 of the AmfloCoupler and Plug catalog. In the coupler shown in the Amflo catalog, theautomatic shut-off valve is spring biased to seal against the opposedside of the cut washer.

At least in the U.S., coupler plugs are not standardized. In fact, threetypes of coupler plugs are in common use, and they differ substantiallyin the outer diameter of the nose of the coupler plug, and in the axialposition of the nose of the coupler plug with respect to the annularretaining groove of the plug. It would be advantageous to provide aquick disconnect coupler that seals reliably against all three commonlyavailable coupler plugs.

A prior art approach to providing a quick disconnect coupler which isintended to seal all three commonly available plugs is to use a U cupseal in the coupler which slides axially along the length of the coupleras necessary to seal against any one of the three plugs. The structureof this prior art coupler is similar to the Hansen AUTO-FLO 20 couplershown in various catalogs of the Tuthill Corporation, Hansen CouplingDivision. In this arrangement, the coupling plug shifts the seal axiallyalong the central passageway of the housing as necessary to bring theseal into sealing engagement with the nose of the plug. The illustrateddesign has a cylindrical, inwardly facing sealing surface, and thesliding seal is spring biased towards the retaining elements by theautomatic shut-off valve.

SUMMARY OF THE INVENTION

This invention relates to an improved sealing arrangement for a quickdisconnect coupler of the type having a housing which defines a centralpassageway, a plurality of retaining elements disposed on respectivesides of the central passageway, means for holding the retainingelements radially inwardly, toward the central passageway, and means formanually overriding the holding means to allow the retaining elements tomove radially outwardly.

According to a first aspect of this invention, a seal retaining memberis movably mounted in the housing to move between first and secondpositions, wherein the first position is closer to the retainingelements than the second position. This seal retaining member has anopening aligned with the central passageway. Means are provided forbiasing the seal retaining member toward the first position. An annularseal is mounted in the seal retaining member around the opening, andthis annular seal defines an axial sealing surface facing towards theretaining elements and a radial sealing surface. The annular seal isconfigured such that it transmits sufficient forces to the sealretaining member to move the seal retaining member to the secondposition in response to a first, larger diameter plug bearing on theaxial sealing surface. The annular seal is also configured to form aradial seal around a second, smaller diameter plug with the sealretaining member in the first position.

Because the annular seal relies on axial sealing for larger plugs andradial sealing for smaller plugs, the seal itself can be made with aminimum volume of a resilient material. The keeper is preferably shapedas described below to center each of the three commonly used couplerplugs. In this way, problems related to the tendency of an elastomericmaterial to take a compression set are reduced, and excellent sealingcharacteristics are provided.

According to a second aspect of this invention a seal retaining memberis movably mounted in the housing to move between first and secondpositions, wherein the first position is closer to the retainingelements than the second position. This seal retaining member defines anopening aligned with the central passageway. At least one seal ismounted on the seal retaining member, which is biased toward the firstposition. The opening in the seal retaining member comprises at leastfirst and second portions, wherein the first portion is closer to theretaining elements than the second portion, wherein the first portion isoperative to center a first, larger diameter plug and defines aneffective diameter of about 0.37 inch, and wherein the second portion isoperative to center a second, smaller diameter plug and defines aneffective diameter of about 0.32 inch.

Because the seal retaining member is free to slide axially, and becausethe opening of the seal defining member includes the first and secondportions defined above, positive centering is provided for plugs ofvarious diameters, thereby improving sealing characteristics of thecoupler.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view in partial section showing a first embodimentof the coupler of this invention juxtaposed with three commonly usedcoupler plugs.

FIG. 2 is a longitudinal sectional view of the coupler of FIG. 1 showingthe preferred embodiment of the seal of this invention.

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2.

FIG. 4a is a side elevational view of the seal retainer of FIG. 2.

FIG. 4b is a cross-sectional view taken line 4b 4b of FIG. 4a.

FIG. 4c is a plan view taken along line 4c-4c of FIG. 4a.

FIGS. 5a, 5b and 5c are partially schematic views of the coupler ofFIGS. 1 and 2, showing the coupler mated with the plugs P1, P2, P3,respectively.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

Turning now to the drawings, FIG. 1 shows a quick disconnect coupler 10which incorporates a presently preferred embodiment of this invention.The coupler 10 is intended to engage and reliably seal any one of threeseparate coupler plugs P1, P2, P3, as shown schematically in FIG. 1.

Each of the plugs defines a shaft S1-S3 which terminates in a noseN1-N3. The shafts S1-S3 define outer diameters D1-D3. Each of the shaftsS1-S3 has an intermediate groove G1-G3 that is engaged by the coupler 10to hold the plug P1-P3 in place. The axial separation between the end ofthe nose N1-N3 and the groove G1-G3 varies from one plug to another, asshown in FIG. 1. Table I lists the dimensions for the diameters D1-D3 ofthe plugs P1-P3, which are conventional coupler plugs known as TRUFLATEshort-nose type plugs, Hansen-type plugs, and ARO-type plugsrespectively.

                  TABLE 1                                                         ______________________________________                                        Diameter    Dimension (Inches)                                                ______________________________________                                        D1          0.359-0.361                                                       D2          0.315-0.318                                                       D3          0.307-0.310                                                       ______________________________________                                    

FIG. 2 shows a cross-sectional view of the coupler 10, which includes ahousing or housing assembly 12. The housing assembly 12 is made up of anouter housing 14 and an inner housing 16, which are threaded together toform an assembly which is rigid in use. The housing assembly 12 definesa central passageway 18 which extends along an axis 20 completelythrough the housing 12. The open end of the central passageway 18 at theouter housing 14 defines an entry portion 22. The entry portion 22 issized large enough to receive the largest one of the shafts S1-S3, andin this embodiment preferably has a diameter of 0.467 inch.

As shown in FIGS. 2 and 3, two retaining elements 24 are mounted inobliquely oriented slots 26 defined in the outer housing 14. Theretaining elements 24 are biased radially inwardly by a washer 28 and acoil spring 30 interposed between the washer 28 and the outer housing14. An outer sleeve 32 surrounds the washer 28 and the coil spring 30and can be moved manually to the right as shown in FIG. 2 to compressthe coil spring 30 and allow the retaining elements 24 to move radiallyoutwardly along the slots 26, to allow one of the plugs P1-P3 to beremoved from the coupler 10.

In this embodiment, the slots 26, the washer 28 and the coil spring 30cooperate to form a biasing means that biases the retaining elements 24radially inwardly into a plug retaining position. The outer sleeve 32cooperates with the washer 28 to form a manual overriding means formanually overriding the coil spring 30 and allowing the retainingelements 24 to move radially outwardly.

Those skilled in the art will recognize that the retaining elements,biasing means and overriding means can take a number of alternate forms.For example, spheres or balls can be substituted for the pins 24, asshown in the Gailey and Karcher, et. al. patents identified above.Similarly, the holding means can take the form of an annular sleeve,also as shown in the Gailey and Karcher, et al. patents.

As shown in FIG. 2, the coupler 10 also includes a valve member 34mounted for axial movement in the central passageway 18. The valvemember 34 defines an annular flange 36 and a tubular forward end 38. Thetubular forward end 38 is pierced by a pair of slots 40, and a spring 42is interposed between the inner housing 16 and the valve member 34 tobias the valve member 34 to the left as shown in FIG. 2. In the absenceof a plug in the coupler 10, the valve member 34 is pushed against awasher 44 such that the flange 36 cooperates with the washer 44 to sealthe central passageway 18. When any of the plugs P1-P3 is locked inposition in the coupler 10, the nose N1-N3 of the plug P1-P3 pushes thevalve member 34 to the right as shown in FIG. 2, thereby lifting theflange 36 off of the washer 44 and allowing fluid communication throughthe slots 40 from one end of the central passageway 18 to the other.

The outer housing 14 defines an annular groove 46 sized to receive thewasher 44. This groove 46 functions as a mounting feature which is fixedin place in the housing 12 and is used to capture the washer 44 in afixed axial position in the housing 12.

A seal retainer 50 is mounted for limited axial movement in a recess 48formed in the housing 12 as described below in conjunction with FIGS. 5athrough 5c. The seal retainer 50 is shown in greater detail in FIGS.4a-4c.

As best seen in FIG. 4b, the seal retainer 50 defines an opening 52extending therethrough. This opening 52 includes a first portion 54having a larger diameter, a groove 56, and a second portion 58 having asmaller diameter. The second portion 58 is in turn made up of twodiameters, one slightly smaller than the other. The face of the sealretainer 50 opposite the first portion 54 defines a raised annular boss60.

Table II provides presently preferred dimensions for the seal retainer50, which can be made from any suitably rigid material, such as CDA 360brass.

                  TABLE II                                                        ______________________________________                                        Reference Symbol                                                              (FIGS. 4a, 4b)                                                                             Dimensions (Inches) or Angle                                     ______________________________________                                        A            .508                                                             B            .395                                                             C            .150                                                             D             .015 R                                                          E            .052                                                             F            .202                                                             G            .432                                                             H            .367                                                             I            .321                                                             J             .015 R                                                          K            .027                                                             L            .083                                                             M            .040                                                             N            .313                                                             O             .015 R                                                          ______________________________________                                    

Preferably the recess 48 is dimensioned to allow about 0.07 inch ofaxial movement to the seal retainer 50.

In use an O-ring 62 is mounted in the groove 56. This O-ring ispreferably a polyurethane ring having an inner diameter of 0.301 inchand a thickness of 0.070 inch. The preferred hardness for the O-ring 62is 90 durometer (Shore A). A suitable O-ring may be obtained fromDisogrin as Part. No. 011-90-250. As described below in conjunction withFIGS. 5a through c, the O-ring 62 as used with the seal retainer 50defines an axial sealing surface 64 and a radial surface sealing 66.

Turning now to FIGS. 5a through 5c, these drawings show in somewhatschematic form the manner in which the coupler 10 seals against thethree plugs P1-P3, respectively. The plug P1 shown in FIG. 5a is thelargest diameter of the three, and the nose N1 is sized to fit withinthe first portion 54 and to bear directly on the axial sealing surface64 of the O-ring 62. The O-ring 62 transmits axial forces to the sealretainer 50, thereby moving the seal retainer 50 rearwardly, toward thewasher 44. The boss 60 deforms the washer 44 rearwardly as shown in FIG.5a. An axial seal is obtained between the nose N1 and the axial sealingsurface 64, and between the boss 60 and the washer 44. Because the noseN1 fits within the first portion 54, the nose N1 is centered by therigid seal retainer 50, and is held in alignment for axial sealing withthe axial sealing surface 64.

As shown in FIG. 5b, the nose N2 of the plug P2 is smaller in diameter,and is sufficiently small to fit within the outer part of the secondportion 58 of the seal retainer 50. Because the nose N2 is dimensionedto pass through the O-ring 62 into the outer part of the second portion58, the seal retainer 50 is not moved rearwardly by the plug P2, and aradial seal is formed between the radial sealing surface 66 of theO-ring 62 and the nose N2. As before, an axial seal is formed betweenthe boss 60 and the washer 44, but with less rearward deformation of thewasher 44. Because the nose N2 fits within the outer part of the secondportion 58, the nose N2 is held in a centered position within thecentral passageway 18 by the seal retainer 50. This minimizes movementof the plug P2, and facilitates adequate sealing, even when large forcesare applied tending to tilt the plug P2 in the coupler 10.

FIG. 5c shows the manner in which the plug P3 is sealed by the coupler10. Note that the nose N3 is received within the inner part of thesecond portion 58, and the seal retainer 50 thereby centers the plug P3.As in FIG. 5b, the plug P3 passes through the O-ring 62 and sealsagainst the radial sealing surface 66. As before, the boss 60 forms anaxial seal with the washer 44.

From the foregoing discussion of FIGS. 5a through 5c, it should beapparent that the seal retainer 50 and the O-ring 62 cooperate with thewasher 44 to accommodate all three plugs P1-P3 effectively. All three ofthe noses N1-N3 are effectively centered by the seal retainer 50, inspite of the fact that they differ significantly in diameter and length.The O-ring 62 is dimensioned so that it is too small in diameter toprovide a radial seal with the nose N1. However, the O-ring 62 isprovided with a configuration and a hardness that allow the O-ring 62 toseal axially against the nose N1.

It is also significant that the washer 44 simultaneously performs fourfunctions. First, the washer 44 defines a rearward axial face 68 thatprovides a sealing surface against the flange 38 of the valve number 34.Second, the washer 44 defines a forwardly facing axial face 70 thatprovides an axial seal against the boss 60. Third, the resilience of thewasher 44 biases the seal retainer 50 to the position of FIGS. 5b and5c, while allowing the seal retainer 50 to move rearwardly as shown inFIG. 5a. Fourth, the washer 44 seals the threaded connection between theinner and outer housings 16, 14.

Of course, it should be understood that a range of changes andmodifications can be made to the preferred embodiment described above.Cut or molded parts can be used for the washer 44, and a variety ofmaterials can be used for the respective components. It is thereforeintended that the foregoing detailed description be regarded asillustrative rather than limiting, and that it be understood that it isthe following claims, including all equivalents, which are intended todefine the scope of this invention.

I claim:
 1. In a quick disconnect coupler of the type comprising:a housing which defines a central passageway which extends along an axis; a plurality of retaining elements disposed on respective sides of the central passageway; a retainer configured to hold the retaining elements radially inwardly, toward the central passageway, said retainer being manually movable to allow the retaining element to move radially outwardly; the improvement comprising: a seal retaining member movably mounted in the housing to move along the axis between first and second positions, wherein the first position is closer to the retaining elements than the second position, said seal retaining member having an opening aligned with the central passageway; a biasing element operative to bias the seal retaining element toward a first position; at least one seal mounted on the seal retaining member; said opening comprising at least first and second positions, wherein said first portion is closer to the retaining elements than the second portion, wherein said first portion is operative to center a first, larger diameter plug and defines an effective diameter of about 0.37 inch, and wherein said second portion is operative to center a second, smaller diameter plug and defines an effective diameter of about 0.32 inch.
 2. The invention of claim 1 wherein said opening additionally defines a third portion, wherein said second portion is closer to the retaining elements than the third portion, and wherein said third portion is operative to center a third plug, smaller in diameter than the second plug, and defines an effective diameter of about 0.31 inch.
 3. The invention of claim 1 wherein the seal retaining member defines a seal receiving groove between the first and second portions of the seal retaining member opening, said groove having a diameter greater than the first diameter.
 4. The invention of claim 3 wherein the seal comprises an O-ring seal disposed in the seal receiving grooves.
 5. The invention of claim 1 wherein the biasing element comprises an elastomeric washer mounted in the housing adjacent the seal retaining member.
 6. The invention of claim 5 wherein the seal retaining member comprises a raised annular boss positioned around the opening to contact the washer.
 7. In a quick disconnect coupler of the type comprising:a housing which defines a central passageway which extends along an axis; a plurality of retaining elements disposed on respective sides of the central passageway; a retainer configured to hold the retaining elements radially inwardly, toward the central passageway, said retainer being manually movable to allow the retaining elements to move radially outwardly; the improvement comprising: a seal retaining member movably mounted in the housing to move along the axis between first and second positions, wherein the first position is closer to the retaining elements than the second position, said seal retaining member having an opening aligned with the central passageway; a biasing element operative to bias the seal retaining element toward a first position; an annular seal mounted in the seal retaining member around the opening, said annular seal defining an axial sealing surface facing toward the retaining elements and a radial sealing surface; said annular seal being configured such that the annular seal transmits sufficient forces to the seal retaining member to move the seal retaining member to the second position in response to a first, larger diameter plug bearing on the axial sealing surface; and said annular seal being configured to form a radial seal around a second, smaller diameter plug with the seal retaining member in the first position.
 8. The invention of claim 7 wherein the seal retaining member opening comprises a first portion oriented toward the retaining elements and a second portion oriented away from the retaining elements, wherein the first portion defines a first diameter, wherein the second portion defines a second diameter, and wherein the first diameter is greater than the second diameter.
 9. The invention of claim 8 wherein the first diameter is sized to receive to first plug and wherein the second diameter is sized to receive the second plug.
 10. The invention of claim 8 wherein the first diameter is about 0.37 inches and the second diameter is about 0.32 inches.
 11. The invention of claim 8 wherein the seal retaining member defines a seal receiving grooves between the first and second portions of the seal retaining member opening, said groove having a diameter greater than the first diameter.
 12. The invention of claim 7 wherein the biasing element comprises an elastomeric washer mounted in the housing adjacent the seal retaining member.
 13. The invention of claim 12 wherein the seal retaining member comprises a raised annular boss positioned around the opening to contact the washer.
 14. The invention of claim 12 wherein the washer defines first and second opposed faces, wherein the seal retaining member axially seals against the first face of the washer, and wherein the coupler comprises a check valve positioned in the central passageway to seal against the second face of the washer.
 15. The invention of claim 8 wherein the second portion additionally defines a third diameter, smaller than the second diameter, wherein the seal is positioned between the first and second diameters, and wherein the third diameter is farther from the seal than the second diameter.
 16. The invention of claim 15 wherein the first, second and third diameters are about 0.37, 0.32 and 0.31 inches, respectively. 